Although you use the --disable-werror option when configuring elfutils,
some -Werror options still being dropped in some Makefiles. We are
applying a patch in Buildroot to fix that problem:

http://patchwork.ozlabs.org/patch/409002/

Could that patch be applied upstream?

Best regards,
-- 
Vicente Olivert Riera
Graduate Software Engineer, MIPS Processor IP
Imagination Technologies Limited
t: +44 (0)113 2429814
www.imgtec.com